Thromboembolism

1
Thromboembolism

• Tintinalli Chap. 60

2
Epidemiology

• 3rd most common cause of death
• 600,000 cases per year 1/3 die
• 30 of untreated PE cause death 2-8 mortality
  if treated

3
Pathophysiology

• Most arise from thrombin in the Deep Venous
  system or heart/kidney/renal/pelvic venous system
• 50 to 80 percent of iliac, femoral, and popliteal
  vein thrombi (proximal vein thrombi) originate
  below the popliteal vein (calf vein thrombi) and
  propagate proximally
• 20 calf thrombi will propagate
• Virchows Triad
• Venous stasis
• Intimal Damage
• Hypercoagulability

4
Risk Factors

• 12 have no established risk factors
• Surgery within 4 weeks
• Obstetrics up to two weeks postpartum
• Malignancy current or tx within 6 months
• Immobilization Hospital, institutional care,
  paresis/paralysis, cast/splint
• Factor Deficiency
• Factor V, Protein C/S, Antithrombin III,
  Antiphospholipid AB, Plasminogen Def, Factor XII
  def, Homocysteinemia, Dysplasminogenemia,
  Dysfibrinogenemia, Prthrombin 2021A Mutation

5
Risk Factors
T Trauma, Travel
H Hypercoaguable, hormone replacement
R Recreational Drugs (heroin)
O Old (age gt60)
M Malignancy
B Birth Control, Blood Grp A
O Obesity, obstetrics
S Surgery, Smoking
I Immobilization
S Sickness
6
Wells for DVT
Criteria Score
Active Cancer 1
Paralysis/immobilization 1
Bedridden 3 days,/surgery last 12wks 1
Tender along deep vein (localized) 1
Entire Leg swollen 1
Unilateral calf swelling gt3cm 1
Pitting edema 1 leg 1
Collateral superficial non-varicose vn 1
Previous DVT 1
Alt Dx likely -2
Score lt2 Low or moderate risk DVT
Socre gt2 High risk for DVT
7
Wells Criteria PE

• Suspected DVT 3
• Alternative Dx likely -3
• Tachycardia gt100 1.5
• Immobilization gt3 days /surgery lt4 wks 1.5
• Previous DVT/PE 1.5
• Hemoptysis 1
• Cancer or Tx within 6 months 1

• Low Suspicion lt2 (3.6)
• Mod Suspicion 2-6 (20.5)
• High Suspicion gt6 (66.7)

8
Christopher Study

• 3306 patients with clinically suspected PE,
  defined as sudden onset of dyspnea, deterioration
  of existing dyspnea, or onset of pleuritic chest
  pain without another apparent cause.
• They divided wells scores into two groups defined
  as lt4 (unlikely) or gt4 (likely).
• 1028 had PE excluded with wells lt4 normal
  d-dimer only 4 none fatal PE diagnosed (0.4)
  one DVT (0.1)
• 1438 had gt4 or lt4 with positive d-dimer and
  underwent CTA 0.6 had a DVT 0.2 had nonfatal
  PE
• 674 had PE diagnosed by CTA only 11 fatal PE
  all had either gt4 wells or elevated d-dimer

9
Signs Symptoms

• PIOPED 1493 patients 933 selected for trial
  755 had a angiogram/VQ 383 had PE
• 80 were dyspneic
• 75 had pleuritic chest pain
• 60 had Cough
• 75 were tachypneic (gt20)
• 45 had tachycardia (gt90)
• 95 had at least one of (dyspnea, tachypnea,
  chest pain)

10
Diagnosis

• First Form Your PRETEST PROBABILITY!

11
Diagnosis

• ECGs
• gt85 abnormal
• Sinus tach most common Rt. Heart Strain RBBB
  P-pulmonale (peaked Ps in inferior leads) S1Q3T3
• ABGs
• Limited value
• 33 have pO2 gt80mmHg
• A-a gradient (5 have no elevation)
• A-a grad 150 (PaCO2/0.8 PaO2)
• Normal grad age/4 4

12
Diagnosis

• Chest Radiograph
• 30 are normal
• 20 have elevated hemi-diaphragm
• 17 will develop parenchymal infiltrates
• Uncommon hamptons hump (round boarder
  infiltrate facing hilum) Westermarks (dilated
  pulmonary vasculature Fleischners Sign (cut off
  pulmonary arterioles

13
Diagnosis

• D-dimer only of value in low probability
  patients
• Sensitivity ranges from 60 (Latex) to 95
  SimpliRed Eliza)
• Specificity 30-70
• NPV 93
• PPV 30
• False Negatives small clots delayed
  presentation (gt7 days)
• False Positives sepsis MI Liver disease
  Advanced Age Trauma Post-Operative HIV
  infection Cancer pregnancy Idiopathic
• Low probability negative D-dimer lt 1-2
  incidence

14
Diagnosis

• Doppler Ultrasound
• 80-90 of PEs arise from DVTs
• Finding a DVT in a symptomatic patient can
  confirm PE
• 40 of asymptomatic patients with DVTs will have
  a PE
• If low probability for PE, positive d-dimer, and
  negative doppler US, some will repeat in on weeks
  time vs. V/Q or CTA.

15
Diagnosis

• V/Q scans
• Back to PIOPED
• Normal V/Q and low pretest probability is 96
  sensitive to R/O PE
• High Probability for PE confirms diagnosis (95)
• 33 of all V/Q scans are read normal
• 10 of all V/Q scans are read high probability
• Everything in between leaves you scratching

16
Diagnosis

• CTA
• Less contrast and morbidity than angiography
• Detects other important Dxs
• False positives tortuous arteries, atelectasis,
  movement artifact
• False negatives smaller defects, subsegmental
  arteries
• Sensitivity 85-90
• Specificity 90-97
• If a patient has a normal CTA, the patient has
  lt1 chance of a bad 6 month outcome!

17
Diagnosis

• PERC
• The following eight factors constitute the PE
  rule-out criteria (PERC)
• Age less than 50 years
• Heart rate less than 100 bpm
• Oxyhemoglobin saturation 95 percent
• No hemoptysis
• No estrogen use
• No prior DVT or PE
• No unilateral leg swelling
• No surgery or trauma requiring hospitalization
  within the past four weeks
• If low probability wells score and PERC rule
  satisfied less than 1 incidence of PE in 45 day
  follow-up
• Over 8000 patient multi-centered study

18
Prognostic Indicators

• Good Prognosis
• No syncope/seizure at presentation
• Age lt 50
• No CHF, COPD, prior PE
• lt 50 pulmonary vascular occlusion
• Normal ECG
• HR/Sys BP lt 0.8
• Troponin I lt0.4
• Normal RV size and function
• Pulse Ox gt94 on RA

• Bad Prognosis
• Syncope/seizure on presentation
• Age gt70
• Hx CHF, COPD, or prior PE
• gt 50 vascular occulsion
• T wave inversion in V1-V4 incomplete RBBB
• HR/Sys BP gt1
• Troponin gt1
• Dilation of RV or hypokinesis
• Pulse Ox lt 94 on RA

19
Treatment

• O2 therapy if hypoxemia is present
• Anticoagulation
• LMWH in hemodynamically stable patients
• Heparin preferred CrCl lt 30, persistent
  hypotension, morbid obesity, increased risk of
  bleeding, thrombolysis being considered
• Hemodynamic Support
• IV fluids first, if 1000cc does not result in
  systolic BP gt 90mmHg, then dopamine/norepinephrine
  
• Thrombolysis
• Level B indications hemodynamically unstable
  with confirmed PE
• Level C indications hemodynamically stable with
  Rt. Ventricular strain

20
Treatment

• UFH - 80 units/kg bolus IV, then 18 units/kg per
  h
• Lovenox - 1 mg/kg SC BID (actual body weight)
• No study has provided a recommendation for max
  dose
• Streptokinase - 250,000 units IV over 30 min
  followed by 100,000 units/h for 24 h
• Urokineas - 4400 units/kg IV over 10 min followed
  by 4000 units/kg per h for 12 h
• Alteplase - 15-mg IV bolus followed by 2-h
  infusion of 85 mg
• Discontinue heparin during infusion

21
Special Circumstances

• When to do Hypercoagulability Workup
• Draw extra blood for protein S/C and antithrombin
  III
• All others are not affected by heparin therapy
• When to start Heparin Empirically
• No contraindication and high pretest probability
  in hypotensive patients or normotensive patients
  with low pulse oximetry
• Massive Obesity (gt500 lbs)
• If CTA unavailable, treat with elevated dimer and
  high pretest probability
• Pregnancy
• CTA with shielded pelvis provides less radiation
  than V/Q
• If positive, treat as non-pregnant patients